Checkout before npm publish unstable (#2919)

Author: JoshMock

.github/workflows/npm-publish-unstable.yml

@@ -67,6 +67,10 @@ jobs:
       contents: write
       id-token: write
     steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        with:
+          persist-credentials: false
+          ref: main
       - name: npm publish
         run: |
           # set unstable version value